sfc: Reschedule any resets scheduled inside efx_pm_freeze()

efx_pm_freeze() sets efx->state = STATE_FINI, which means
efx_reset_work() will abort any scheduled resets.

efx_pm_thaw() should reschedule efx_reset_work() again,
since a freeze/thaw will not have reset the hardware.

This bug was spotted by inspection - there is no real world example of
this happening.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>